1. Field of the Invention
The present invention relates to a concealed type slide fastener with a separable bottom end stop in which a folded portion of a fastener tape, where the separable bottom end stop in the concealed type slide fastener is attached, is reinforced and protected.
2. Description of the Related Art
Conventionally, Japanese Patent Application Laid-Open No. 6-245806 has disclosed a separable bottom end stop attaching portion of a concealed type slide fastener, in which a space portion having no fastener elements is formed in a fastener tape of a long fastener chain, the space portion is soaked entirely with synthetic resin liquid, an opposing edge portion of the fastener tape is formed by heat so as to be inverted into a U shape and hardened, and then, the fastener tape of the space portion is cut, and a box pin and an insert pin of the separable bottom end stop are formed by injection molding with synthetic resin and attached to the fastener tape respectively, thereby reinforcing a portion of the fastener tape on which a separable bottom end stop is to be attached.
Additionally, a separable bottom end stop of a concealed type slide fastener is known, in which a synthetic resin film is fused on a rear face of a fastener tape and the fastener tape is formed in a U-shape in order to hold a strength of a portion of the fastener tape of the concealed type slide fastener to which the separable bottom end stop is to be attached and to gain a soft texture on a surface of the fastener tape, and then, a box pin and a insert pin are respectively attached to the U-shaped portion.
As mentioned in a preceding paragraph, the separable bottom end stop attaching portion, in which the opposing edge portion of the fastener tape is formed by heat so as to be inverted into a U shape by soaking the space portion in the fastener chain of the concealed type slide fastener, should be mentioned specially, because the separable bottom end stop could be attached to the concealed type slide fastener for the first time and the concealed type slide fastener with the separable bottom end stop is put in practical use. However, it is a problem that the fastener tape at the space portion of the fastener chain becomes very stiff so that this portion gives a feeling of disharmony as a product. For the reason, a concealed type slide fastener is considered and produced, in which synthetic resin film is fused on the rear face of the fastener tape so as to reinforce the separable bottom end stop attaching portion and provide with the soft texture. However, according to this concealed type slide fastener, when the insert pin of the separable bottom end stop is inserted into the box upon its use, the fastener tape at the U-shaped folded edge portion of the space portion comes into sliding contact with a diamond of a slider, so that it is worn and it becomes loose thereby indicating that this fastener tape cannot bear a long term use.
The invention has been achieved in views of this problem. That is, a main object of the invention is provide a concealed type slide fastener with a separable bottom end stop, wherein a front surface of a space portion, which has no fastener elements and to which the separable bottom end stop is attached, in the fastener tape of the concealed type slide fastener is provided with some extent of plasticity and a fastener tape at a U-shaped edge portion of the space portion is prevented to be worn and loose by its sliding contact with a diamond of a slider when an insert pin is inserted into a slider and a box, thereby ensuring a long term use.
Further, an object of the invention is to provide a concealed type slide fastener with a separable bottom end stop having a good appearance, wherein a core cord and sewing yarns left at the space portion of the fastener chain of the concealed type slide fastener as a fastener element removed portion is covered and protected together with the fastener tape by a sequence of a reinforcement tape. Alternately, it is another object of the invention to provide a concealed type slide fastener with a separable bottom end stop wherein the core cord and sewing yarns left at the space portion of the fastener chain of the concealed type slide fastener as the fastener element removed portion and the fastener tape are covered with separate reinforcement tapes, so that the U-shaped edge portion is reinforced firmly and such a slide fastener is produced easily.
And further, an object of the invention is to provide a concealed type slide fastener with a separable bottom end stop, wherein the space portion of the fastener chain of the concealed type slide fastener is protected at both front and rear surfaces thereof by synthetic resin film so as to form a firm space portion.
Furthermore, an object of the invention is to provide a concealed type slide fastener with a separable bottom end stop, wherein the box pin and insert pin of the separable bottom end stop can be attached such that the U-shaped edge portion at the space portion of the fastener chain of the concealed type slide fastener is utilized effectively.